Big Idea: There are different levels of cloud “service” and different ways it’s deployed.

Cloud Service Models (what you rent):

• IaaS (Infrastructure as a Service): You rent raw computing resources (servers, storage, networks). Example: AWS EC2, Azure Virtual Machines.
• PaaS (Platform as a Service): You rent a platform to build/run apps without managing servers. Example: Google App Engine, Heroku.
• SaaS (Software as a Service): You rent access to software over the internet. Example: Gmail, Office 365, Spotify.

Cloud Deployment Models (where it runs):

• Public Cloud: Shared resources, owned by a provider (AWS, Azure, GCP).
• Private Cloud: Resources used only by one org, usually for sensitive data.
• Hybrid Cloud: Mix of both → e.g., hospital runs patient records privately but uses public cloud for email.

Key Takeaway: Cloud isn’t “one thing” — it’s a menu of service and deployment options.